Study: 30% of COVID patients had rebound after 2 days without symptoms
Nearly one third of 158 untreated COVID-19 patients experienced symptom rebound after being symptom-free for at least 2 consecutive days, finds a study of US adults published yesterday in JAMA Network Open.
A team led by researchers from the University of California at San Diego and Harvard University investigated whether the symptom rebound often attributed to treatment with the antiviral drug nirmatrelvir-ritonavir (Paxlovid) is simply part of the natural course of some COVID-19 cases.
The researchers said that the biological underpinning of COVID-19 rebound after Paxlovid treatment is unclear but may include rapid clearance of nirmatrelvir, delayed immune responses, or the development of drug resistance. Study participants completed a daily diary of 13 symptoms for 28 days in 2020. Median patient age was 47 years, and median time from symptom onset to enrollment was 6 days.
During follow-up, 68% of patients reported symptom resolution, of which 44% (30% of all participants) later reported recurrence of at least 1 of the 13 symptoms. Eighty-five percent said their symptoms were mild, and 15% reported at least one moderate symptom.
The most common rebound symptoms were cough (44%), fatigue (35%), and headache (35%), similar to those reported at enrollment (except that pain and aches were reported more often at enrollment), and to those of patients who still had symptoms at the end of the study. Eight patients (5%) were hospitalized, but none died.
The researchers cautioned that the study was conducted before COVID-19 vaccines became available and during periods dominated by wild-type SARS-CoV-2 and the Alpha variant and thus may not be generalizable to current conditions.
"We found the natural history of untreated COVID-19 was variable and undulating," the authors wrote, adding that rebound symptoms are not predictive of severe disease. "Our observed variation may explain some of the rebound of symptoms after treatment for COVID-19, like in cases of what has been described as Paxlovid rebound."
Oct 27 JAMA Netw Open research letter
COVID-19 vaccines linked to lower ICU admissions for pneumonia
A new study in JAMA Network Open based on Italian intensive care unit (ICU) admissions shows that COVID-19 vaccination was tied to lower rates of ICU admissions due to pneumonia but was not associated with a reduction in hospital mortality.
The cohort study was based on vaccine records of 10 million residents of the Lombardy region of Italy from Aug 1 to Dec 15, 2021. The median age was 48, and 51% of residents were female. As of Jan 31, 2022, a total of 7,863,417 residents were vaccinated; 79.5%; received an mRNA vaccine, 7.0%; received an adenoviral vector vaccine (AdV), 13.5% received a mix of vaccines, and 57.2% were boosted.
There were 553 patients admitted to an ICU for COVID-19 pneumonia during the study period, of whom 139 (25.1%) were vaccinated and 414 (74.9%) were unvaccinated. Adjusting for age, sex, time from the last administered dose, and vaccine type, the risk of ICU admission remained lower in vaccinated individuals compared with those unvaccinated, the authors said.
The lowest incident rate ratios (IRRs) (0.03; 95% confidence interval [CI], 0.03 to 0.04; P < .001) were among individuals who had received an mRNA vaccine within 120 days and translate to 97% protection from ICU illness. The highest IRR (0.21; 95% CI, 0.19 to 0.24; P < .001), or 79% protection, was among individuals who had a time from the last administered dose of an AdV vaccine of more than 120 days.
"Even 4 months after vaccine administration, vaccinated individuals still had a 4.5-times lower risk of ICU admission compared with unvaccinated individuals. Furthermore, mRNA vaccines maintained a greater and more prolonged effectiveness in preventing ICU admission compared with AdV," the authors wrote.
Hospital mortality rates were not, however, significantly affected by vaccination status, with crude mortality rates ranging from 23% to 33% for vaccinated patients and 22% and 29% for unvaccinated patient. The authors said this was likely due to advanced patient age and comorbidities.
Oct 27 JAMA Netw Open study
CDC reports more flu rises, first pediatric death of the season
US flu activity continued its early rise last week, with the first pediatric flu death of the new season reported and hospitalization rates already rising, the Centers for Disease Control and Prevention (CDC) said today in its weekly update.
The pediatric flu death involved an H3N2 virus and occurred during the week that ended on Oct 8. The CDC said the cumulative hospitalization rate for flu last week was 1.5 per 100,000 population, which is at the highest level for this point of the season since 2010-11. More than 94% of flu hospitalizations involved influenza A, and of subtyped samples, 72.9% were the H3N2 strain. Rates were highest in seniors and in children up to age 4 years.
Other markers that the CDC uses to track flu activity also rose, including the percentage of outpatient visits for flu, a measure that can also reflect activity from other respiratory viruses that have similar symptoms.
The southeast and south-central regions are still reporting the highest flu levels. The percentage of respiratory samples that tested positive for flu increased last week in most parts of the country, to 6.2% overall.
The CDC recommends that everyone age 6 months and older receive a flu vaccine, which it says is the best way to protect against flu and serious outcomes in people with are vaccinated but still get sick. This year, federal health officials have urged the public to get vaccinated against flu at the same time they receive updated COVID-19 boosters.
Oct 28 CDC FluView update
Three countries report new polio cases
Three countries have new polio cases this week, all vaccine-derived types. The Democratic Republic of the Congo (DRC), Niger, and Nigeria all recorded new cases, according to the weekly report published by the Global Polio Eradication Initiative (GPEI).
Niger and Nigeria each reported a single case of circulating vaccine-derived poliovirus type 2 (cVDPV2). In Niger the case was reported in Maradi. There are now 11 cases in 2022, and 18 were reported in 2021.
Nigeria's case was recorded in Borno, raising the yearly total to 37 cases. There were 415 cases reported in 2021.
The DRC is intensifying its outbreak response as one case of circulating vaccine-derived poliovirus type 1 (cVDPV1) was reported in Haut Lomami. There are now 29 cases reported in 2022. Six new cases of cVDPV2 were reported, bringing the number of such cases reported in 2022 to 160. The country had 28 cVDPV2 cases in 2021.
Oct 28 GPEI report